Marble cake is a cake made by swirling two or more differently colored or flavored batters - classically vanilla and chocolate - together in the pan before baking, producing a marbled pattern in the crumb. It likely emerged in Germany and the United States during the 19th century and remains a fixture of German coffee-and-cake culture, where it's known as Marmorkuchen. It's typically served plain, dusted with powdered sugar, or topped with a simple glaze, prized for a moist, tender crumb and the interplay of its two batters. Modern versions swap in flavors like red velvet, coffee, or fruit purees for one of the batters.